Police are investigating whether an armed robbery in Surrey today is to the hunt for escaped prisoner Michael Wheatley, also known as the 'Skull Cracker'.

The 55-year previously held up the same branch of the Chelsea Building Society in Sunbury-on-Thames in July 2001.

Firearms officers are at the scene of the robbery.

Kent Police have confirmed they are looking into a possible link between the robbery and 55-year-old Wheatley.

Staff at nearby businesses told Sky News that officers had informed them they believed Wheatley was responsible for the raid, which took place at 10.20am.

Surrey Police said: "(The man) threatened a member of staff with a handgun before demanding money from a safe and escaping with a quantity of cash.

Image:A still from CCTV footage of one of Wheatley's robberies

"The member of staff was left shaken but unhurt. At this time it is unknown whether the weapon was genuine or an imitation."

The suspect is described as being in his late 40s or early 50s, around six foot tall with a slim to medium build and short grey hair.

Video:UK Open Prison System Explained

He was also wearing jeans and a light blue denim jacket, as well as a woolly hat and dark-rimmed glasses, police said.

The man left the building society on foot but officers are investigating the possibility he may have got into a vehicle.

Wheatley, who earned his nickname for pistol-whipping victims, failed to return to HMP Standford Hill - an open prison on the Isle of Sheppey, Kent - after being temporarily released.

He was given 13 life sentences in 2002 for a string of brutal raids on banks and building societies.

Sky News Home Affairs Correspondent Mark White said it was the "worst case scenario for the authorities" if Wheatley is confirmed as the man behind today's raid.

Video:Woman's 'Skull Cracker' Ordeal

The robbery comes after a reported sighting of Wheatley in Twickenham on Monday.

Police searched the area but failed to find the fugitive.

A full review has been ordered into prison security following his escape.

Justice Secretary Chris Grayling told Sky News he was unhappy with the system for releasing prisoners on temporary licence and said changes were being made, including tighter risk assessments and tagging of prisoners.

He said: "I'm carrying out a full inquiry into the circumstances of the case. Every situation like this is unacceptable."

Video:Grayling On The 'Skull Cracker'

Members of the public are urged by police not to approach Wheatley, but to dial 999.

He carried out 13 raids between June 2001 and April 2002 in bank branches from Southampton in Hampshire to Royston in Hertfordshire.

Police say Wheatley, originally of Limehouse, east London, has links across southeast England.